Fungus already shows promise as a "green" form of leather and protective packaging. Thanks to new research, it has now also found use in an environmentally-friendly sound-absorbing material.
Acoustic insulation is currently made of synthetic or mineral-based materials, neither of which are easily recyclable – their production processes also aren't always very eco-friendly. Instead, scientists at Germany's Fraunhofer Institute for Environmental, Safety and Energy Technology looked to mycelium.
Mycelium is the vegetative component of fungus, and it's made up of thread-like structures known as hyphae. The researchers harvested mycelium grown in a lab, then added it to a substrate consisting of straw, wood fibers, and waste from the food production industry. That mixture was then 3D-printed into the desired shape.
The hyphae proceeded to grow throughout the three-dimensional matrix, forming it into a free-standing solid. Once that point was reached, the material was dried in a high-temperature kiln, killing the fungus to keep it from growing further. What resulted was a porous open-cell structure that was "ideal for soundproofing purposes."
Not only is the material made entirely from renewable, biodegradable ingredients – some of which would otherwise be discarded – but because it's 3D printed, it can also be manufactured with internal structures optimized for absorbing sound. Further research is needed to determine which structures would work best.
Source: Fraunhofer
